Ensure that rules without strict slashes match paths with slashes

A rule defined as `/path` with strict-slashes == False should match a
path `/path/` but only if there isn't a rule that directly matches
`/path/`. This restores the previous 2.2.0 behaviour.

Author: pgjones

CHANGES.rst

@@ -5,6 +5,9 @@ Version 2.2.1
 
 Unreleased
 
+-   Fix router so that ``/path/`` will match a rule ``/path`` if strict
+    slashes mode is disabled for the rule. :issue:`2467`
+
 
 Version 2.2.0
 -------------

src/werkzeug/routing/matcher.py

@@ -129,6 +129,22 @@ def _match(
                     rv = _match(new_state, remaining, values + list(match.groups()))
                     if rv is not None:
                         return rv
+
+            # If there is no match and the only part left is a
+            # trailing slash ("") consider rules that aren't
+            # strict-slashes as these should match if there is a final
+            # slash part.
+            if parts == [""]:
+                for rule in state.rules:
+                    if rule.strict_slashes:
+                        continue
+                    if rule.methods is not None and method not in rule.methods:
+                        have_match_for.update(rule.methods)
+                    elif rule.websocket != websocket:
+                        websocket_mismatch = True
+                    else:
+                        return rule, values
+
             return None
 
         try:

tests/test_routing.py

@@ -219,6 +219,7 @@ def test_strict_slashes_leaves_dont_consume():
             r.Rule("/path3/", endpoint="branch", strict_slashes=False),
             r.Rule("/path4", endpoint="leaf", strict_slashes=False),
             r.Rule("/path4/", endpoint="branch", strict_slashes=False),
+            r.Rule("/path5", endpoint="leaf"),
         ],
         strict_slashes=False,
     )
@@ -233,6 +234,7 @@ def test_strict_slashes_leaves_dont_consume():
     assert adapter.match("/path3/", method="GET") == ("branch", {})
     assert adapter.match("/path4", method="GET") == ("leaf", {})
     assert adapter.match("/path4/", method="GET") == ("branch", {})
+    assert adapter.match("/path5/", method="GET") == ("leaf", {})
 
 
 def test_environ_defaults():